Not Applicable
Not Applicable
1. Field of the Invention
This invention relates to electronic article surveillance (EAS) tags, and more particularly, to an EAS tag with improved anti-defeat mechanisms.
2. Description of the Related Art
Electronic article surveillance systems are well known in the art and are used for inventory control and to prevent theft and similar unauthorized removal of articles from a controlled area. Typically, in such systems a system transmitter and a system receiver are used to establish a surveillance zone, which must be traversed by any articles being removed from the controlled area. An EAS tag is affixed to each article and includes a marker or sensor adapted to interact with a signal being transmitted by the system transmitter into the surveillance zone. This interaction causes a further signal to be established in the surveillance zone which further signal is received by the system receiver. Accordingly, upon movement of a tagged article through the surveillance zone, a signal will be received by the system receiver, identifying the unauthorized presence of the tagged article in the zone.
Certain types of EAS tags are deactivatable, are disposable, and may be permanently affixed to articles. Other types of EAS tags have been designed to be reusable and, thus, include releasable attachment devices for affixing the tags to the articles. Such attachment devices are further designed to be releasable by authorized personnel only so that unauthorized removal of a tag from its article is avoided. To this end, many attachment devices are made releasable only through the use of an associated special tool or detaching mechanism.
U.S. Pat. No. 5,426,419, entitled Security Tag Having Arcuate Channel and Detacher Apparatus for Same, (the ""419 patent) the disclosure of which is incorporated herein by reference, discloses an EAS tag that has a relatively hard tag body, which is adapted to be releasable from an article in an easy and simple manner by insertion of the arcuate probe of an associated detacher device into an arcuate channel of the tag to release a spring clamp mechanism. The spring clamp mechanism is a releasable locking mechanism that prevents removal of a tack assembly that is adapted for insertion through an article, which is captured when inserted into an opening in a portion of the tag body.
FIGS. 1-7 show various views of an EAS tag 1 in accordance with the principles of the invention disclosed in the ""419 patent, a portion of the description of which follows herein. As shown in FIG. 1, the tag 1 includes an upper housing 2 having side walls 2A, 2B, 2C and 2D which are joined by a top wall 2E. The tag 1 also includes a lower housing 3 having side walls 3A, 3B, 3C and 3D which are joined by a bottom wall 3E. The upper and lower housings 2 and 3 are joined or mated along corresponding or associated side wall pairs (2A, 3A), (2B, 3B), (2C, 3C) and (2D, 3D) to form a closed tag body 1A.
The housings 2 and 3 are preferably made of a hard or rigid material. A usable rigid or hard material might be a hard plastic such as, for example, an injection molded ABS plastic. If a plastic is used, the mating side walls of the housings can be joined by an ultrasonic weld 1B or like joining mechanism.
The tag 1 further includes a tack assembly 4 shown as having an enlarged tack head 4A and an elongated tack body 4B provided with slots or grooves 4C and a pointed forward end 4D (see, FIGS. 1, 2 and 6A). The tack assembly 4 is used to attach the tag body 1A to an article 51, which is to be protected by the EAS tag 1.
In order to sense the tag 1 and, therefore, detect the presence of the tag and the attached article 51, the inner surfaces 2F and 3F of the walls 2E and 3E of the housings 2 and 3 are provided with frame members 2G and 3G which together define an interior cavity 1C for receiving an EAS sensor 5 (see, FIGS. 2, 3 and 4A). The EAS sensor 5 can be any sensor that generates detectable EAS signals, and may be an acoustically or mechanically resonant magnetic sensor such as, but not limited to, that disclosed in U.S. Pat. Nos. 4,510,489 and 4,510,490. Possible other magnetic EAS sensors usable for the sensor 5 might be, but not limited to, those disclosed in U.S. Pat. Nos. 4,686,516 and 4,797,658 and possible RF EAS sensors might be, but not limited to, those disclosed in U.S. Pat. Nos. 4,429,302 and 4,356,477.
As above-noted, the article 51 is joined to the tag body 1A by the tack assembly 4. This is accomplished by inserting the tack body 4B into an opening 2H in the wall 2E of the upper housing 2. When the tack body 4B is fully inserted, the pointed end 4D of the tack is received in an upstanding cavity or collar 3H extending from the inner surface 3F of the lower housing wall 3E. The tack head 4A, in turn, seats in a recessed area 21 in the upper surface 2J of the wall 2E. The article 51 is thus held between the tack head 4A and the latter wall.
Member 6 to be discussed in greater detail below is provided within the tag body 1A for releasably preventing the tack body from being withdrawn from the tag body. The tack assembly 4B and the article 51 thus become releasably locked to the EAS tag by the member 6.
The EAS tag 1 is further adapted so that access to the member 6 for releasing same is made difficult for other than authorized personnel. To this end, the tag body 1A is configured so that access to the member 6 is through an arcuate channel 7 (see FIGS. 1, 3, 4A, 4B, 6A and 6B) defined by one or more inner walls and by parts of the side walls and upper and lower walls of the tag body 1A. With this configuration, a special arcuate probe 8 is needed to reach and release the member 6 and, thus, detach the tack assembly 4 and the article from the tag body 1A.
As shown, the arcuate channel 7 is defined by a curved inner wall 7A. This wall extends upward from the inner surface 3F of the bottom housing 3 to abut the inner surface 2F of the upper housing 2. The wall 7A is further spaced from the side wall 3D of the bottom housing 3 and its outward end 7Axe2x80x2 terminates at an inward curved part 3Axe2x80x2 of the side wall 3A. The inward curved part 3Axe2x80x2 of the wall 3A results in a space or slot 9A between the side walls 3A and 3D of the lower housing 3.
The slot 9A cooperates with a similar slot 9B between the sides wall 2A and 2D of the upper housing 2 to define a second opening 9 for providing entry or access into the outward end 7xe2x80x2 of the channel 7. At this entry point, the side wall 2A also curves inwardly at a part 2Axe2x80x2, the latter part 2Axe2x80x2 mating with the curved side wall part 3Axe2x80x2 of the side wall 3 of the lower housing 3.
The channel 7 is further defined by a second curved wall 7B (see, FIGS. 4A and 7) extending downwardly from the inner surface 2F of the upper housing 2. The wall 7B is situated outward of the inner end 7Axe2x80x3 of the curved wall 7A and extends beyond this end to the frame member 2G.
The presence of the wall 7B changes or alters the configuration of the channel 7 at its inner end 7xe2x80x3 which end lies adjacent the member 6 (see, FIG. 6B). This change or alteration in configuration defines a keyway for the channel 7 which must be accommodated by the probe 8 to pass through the channel and gain access to the member 6.
The wall 7B changes the channel cross section from substantially rectangular to substantially L-shaped. This is illustrated in the cross section of FIG. 7 which has been taken along the line Bxe2x80x94B in FIG. 1 so that the cross section of the channel end 7xe2x80x3 is made visible.
FIGS. 6A and 6B are enlarged views of the section of the lower housing 3 containing the member 6 and the arcuate channel 7. In FIG. 6A, the arcuate probe 8 is shown as received in and guided by the channel 7 to the member 6 for the purpose of releasing same. As can be seen, the forward end 8A of probe 8 is L-shaped and, thus, fit within the L-shaped keyway defined by inner end 7xe2x80x3 of the channel. In FIG. 6B, the probe 8 is shown as withdrawn from the channel.
Adjacent the inner end 7xe2x80x3 of the channel 7, the lower and upper housings 2 and 3 are provided with further curved walls 9 and 11 which terminate in wall sections 9A and 11A abutting the end walls 2D and 3D. The walls 9 and 11 are outward of the channel 7 and, with the end walls 2D and 3D, define a trap area 13, which prevents access to the member 6. This area provides a safety measure for blocking unauthorized objects introduced into the channel 7 of the tag body 1A in an attempt reach the member 6.
As above-noted, the member 6 is adapted to releasably prevent the tack body 4B from being withdrawn from the tag body 1A. More particularly, the member 6 is specifically adapted to accommodate release of the tack body 4B via the arcuate probe 8 moving in the arcuate channel 7. The member 6 is shown in detail in FIGS. 6A and 6B and in an exploded view in FIG. 5.
As shown, the member 6 is in the form of a spring clamp having a clamp body 14 and jaws 15 and 16. The clamp body includes a mounting part 14A extending laterally of the jaw 15 and a release part 144B extending laterally of the jaw 16. The mounting part 14A includes a mounting aperture 14Axe2x80x2.
Each of the jaws 15, 16 extends outwardly of the plane of the clamp body 14 and then inwardly toward the other jaw. The jaws 15, 16, furthermore, terminate in facing edges 15A and 16A. These edges extend from a common edge 14C of the clamp body 14 inwardly toward each other, then curve outwardly away from each other to define an aperture 14Cxe2x80x2 (typically, circular or elliptical) for receiving the tack body 4B. The edges 15A and 16A then continue in aligned fashion and end in an elongated, lateral slot 14D in the clamp body 14. The latter slot lies inward of a further clamp body edge 14E, which opposes the clamp body edge 14C.
A further laterally extending elongated spring sleeve or arm 17 is attached by a joint area 18 to the side 14Exe2x80x2 of the edge 14E bordering the mounting part 14A. The sleeve 17 extends along the length of the edge 14E and is also out of the plane of the clamp body.
For mounting and supporting the spring clamp 14, the lower housing 3 of the tag body 1A includes a hollow circular mount 21 with a lip 21A and support walls 22, 23 and 24 (see, FIGS. 2, 3, 6A and 6B). The clamp is mounted, via the aperture 14Axe2x80x2 of the mounting part 14, on the mount 21 with the area of mounting part adjoining the aperture 14Axe2x80x2 supported on the lip 21A. A circular wall 25 of the upper housing 3 and a central cylindrical stud 26 of this housing (see, FIGS. 2 and 4A) maintain the mounting part 14A in its mounted position, while allowing the mounting part to be rotated. The spring clamp 14 is thus able to pivot about the mounting part as will be described more fully below.
The back end 14Axe2x80x3 of the mounting part 14A and the lateral part of the clamp connecting the mounting part 14A and the release part 14B are supported on the support walls 22 and 24, while the release part is carried by the wall 23. The spring sleeve 17 rests with one end 17A in a slot 24A in the support wall 24.
When the pointed end 4D of the tack body 4B is introduced in the downward direction through the opening 2H in the upper housing 2, the part 2K of the upper housing, which part is shaped to fit within the hollow of the spring clamp body 14 above the jaws 15, 16 and carries the opening 2H, directs the tack body to the aperture 14Cxe2x80x2 defined by the facing edges 15A, 16A of the jaws. This causes the jaws to spread or open and allow the tack body 4B to pass through the jaws.
When the downward tack travel is stopped at a desired slot 4C, i.e., a slot which provides a tight fit of the tack head 4A and article 51 to the wall 2E of upper housing 2, the jaws 15, 16 retract and clutch the tack body 4B. In this position, the jaws 15, 16 prevent upward movement of the tack 4. The tack 4 and article 51 thus become locked to the tag body 1A.
In order to release the tack 4 from the tag body 1A, the arcuate probe 8 is now introduced into the opening of the tag body 1A via rotation of the probe about its rearward end 8B. This causes the probe to be moved in and guided by the channel 7 until the L-shaped forward end 8A of the probe reaches and passes into the L-shaped inner end 7xe2x80x3 of the channel 7. This brings the probe end 8A to the part of the common edge 14C bordering the release part 14B of the clamp body 14.
Continued rotational movement of the probe 8 then causes a force on the release part 14B. This force, in turn, causes the clamp body 14 to rotate about the support area 14A on the mount 21. The jaws 15, 16 are thus enabled to spread apart or open due to the force of the tack body 4B, which is held stationary by the collar 3H, acting on the walls of the aperture 14Cxe2x80x2. The aperture 14Cxe2x80x2 thus expands, releasing the tack body 4B from the grip or clutch of the jaws. The tack 4 can now be moved in the upward direction past the jaws, via an upward force on the tack head 4A, thereby withdrawing and separating the tack body 4B from the tag body 1A and the article 51 from the tag 1.
During rotation of the spring clamp body 14 as a result of the in-plane force exerted by the probe 8, the spring arm 17 at the joint 18 is compressed. After the tack 4 is separated from the tag body 1A, the probe 8 is rotated in the reverse direction. This reverse rotation disengages the probe from the release part 14A of the spring clamp 14 as the probe 8 is withdrawn from the channel 7. The force on the spring clamp 14 is thus removed and the spring arm 17 expands. This causes the spring clamp 14 to rotate in the opposite direction about the support area 14A. The spring clamp 14 is thereby brought back to its original position awaiting reentry of the tack body 4B for again attaching an article to the tag 1.
Detaching assemblies which incorporate the arcuate detaching probe 8, and can be used to rotate the probe as above-described to detach the tack 4 from the tag 1 are fully illustrated in the ""419 patent, which has been incorporated herein by reference. It should be noted that the spring clamp 14 of the tag 1 can be constructed of spring sheet metal. The probe 8, in turn, can be constructed of hardened tool steel.
The EAS tag of the ""419 patent is difficult to defeat, but attempts are constantly made to defeat the tags by damaging the tags or by unauthorized removal of the tags from the article to which they are attached to prevent detection of the articles as they pass through the surveillance zones. Once an EAS tag is put into service, attempts at unauthorized removal begin. After a period of time, defeating techniques may become known to persons wanting to remove articles undetected by associated EAS systems. Modifications and improvements to the EAS tag become a natural progression in an attempt to stay ahead of the known defeat techniques. U.S. patent application Ser. No. 09/634,236, filed on Aug. 8, 2000, the disclosure of which is incorporated herein by reference, illustrates certain improvements to the EAS tag disclosed in the ""419 patent to make defeating the tag more difficult. Further improvements to prevent unauthorized tag defeats are disclosed hereinbelow.
In accordance with a first aspect of the present invention, an electronic article surveillance tag is provided in which the tag includes a tag body and with a tack assembly for attaching the tag body to an article. The tack assembly includes a tack head and a tack body, which is receivable in the tag body and the tag body is provided with a preventing mechanism for releasably preventing withdrawal of the tack body. Channel defining structure within the tag body defines an arcuate channel. This channel leads to the preventing mechanism and permits an arcuate probe to be guided to such mechanism for releasing same. Release of the preventing mechanism permits withdrawal of tack body thereby separating the tack assembly and article from the tag body. A sensor detectable by an electronic article surveillance system is disposed in said tag body. A shield is provided in said tag body adjacent the sensor to prevent insertion of an instrument through the tag body and into the sensor to damage the sensor.
The preventing mechanism can include a receiving and clutching mechanism, which receives and clutches the tack body, thereby preventing withdrawal of the tack body from the tag body. A release part of the receiving and clutching mechanism when engaged causes the receiving and clutching mechanism to release, thereby allowing withdrawal of the tack body. A second opening in the tag body leads to the arcuate channel which, in turn, leads to the release part of the receiving and clutching mechanism to allow the arcuate probe to engage same to effect the release. A shield is disposed in the tag body adjacent the releasing and clutching mechanism to prevent unauthorized release of the receiving and clutching mechanism by other than the arcuate probe.
The above described shield in said tag body adjacent the sensor to prevent insertion of an instrument through the tag body and into the sensor to damage the sensor can be included in the tag body with the shield used to prevent unauthorized release of the tack assembly.
In a second aspect of the present invention, an electronic article surveillance tag is provided in which the tag includes a tag body and with a tack assembly for attaching the tag body to an article. The tack assembly includes a tack head and a tack body, which is receivable in the tag body and the tag body is provided with a preventing mechanism for releasably preventing withdrawal of the tack body. Channel defining structure within the tag body defines an arcuate channel. This channel leads to the preventing mechanism and permits an arcuate probe to be guided to such mechanism for releasing same. Release of the preventing mechanism permits withdrawal of tack body thereby separating the tack assembly and article from the tag body. A sensor detectable by an electronic article surveillance system is disposed in said tag body. An alarm is disposed within the tag body, for sounding an audible alarm if the tack assembly is withdrawn from the tag body without the arcuate probe being guided through the arcuate channel to the preventing mechanism.
An LED or other light-emitting device can be made visible on the exterior of the tag body to periodically flash when the alarm is armed.
A plurality of relatively small apertures can be disposed on the tag body to permit the audible sound from the alarm to travel from the interior of the tag body to the exterior of the tag body. The plurality of apertures covers a sufficient portion of the tag body to prevent external localization of the position within the tag body of a sound emitting mechanism for generating the sound from the alarm.
A magnet switch for triggering the alarm when a relatively strong magnetic field is incident on the tag body can be included.
The preventing mechanism can include a receiving and clutching mechanism, which receives and clutches the tack body, thereby preventing withdrawal of the tack body from the tag body. A release part of the receiving and clutching mechanism when engaged causes the receiving and clutching mechanism to release, thereby allowing withdrawal of the tack body. A second opening in the tag body leads to the arcuate channel which, in turn, leads to the release part of the receiving and clutching mechanism to allow the arcuate probe to engage same to effect the release. A first switch put into a first state by the tack body upon insertion into the tag body. A second switch put into a first state by the tack head upon insertion of the tack body into the tag body. A third switch put into a first state by the arcuate probe when the arcuate probe is introduced into the arcuate channel to engage the receiving and clutching mechanism. The alarm sounds when the first switch is put into a second state without the third switch in its first state, and the alarm also sounds when the second switch is put into a second state without the third switch in its first state.
A lanyard can be used to attach the tag to an article. The alarm can sound when the lanyard is cut or broken or otherwise becomes discontinuous.
In a third aspect of the present invention, an electronic article surveillance tag is provided in which the tag includes a tag body and with a tack assembly for attaching the tag body to an article. The tack assembly includes a tack head and a tack body, which is receivable in the tag body and the tag body is provided with a preventing mechanism for releasably preventing withdrawal of the tack body. Channel defining structure within the tag body defines an arcuate channel. This channel leads to the preventing mechanism and permits an arcuate probe to be guided to such mechanism for releasing same. Release of the preventing mechanism permits withdrawal of tack body thereby separating the tack assembly and article from the tag body. A sensor detectable by an electronic article surveillance system is disposed in said tag body. An LED or other light-emitting device can be made visible on the exterior of the tag body to periodically flash to simulate that the tag contains an armed alarm.
In a fourth aspect of the present invention, an electronic article surveillance tag is provided in which the tag includes a tag body and with a tack assembly for attaching the tag body to an article. The tack assembly includes a tack head and a tack body, which is receivable in the tag body and the tag body is provided with a preventing mechanism for releasably preventing withdrawal of the tack body. Channel defining structure within the tag body defines an arcuate channel. This channel leads to the preventing mechanism and permits an arcuate probe to be guided to such mechanism for releasing same. Release of the preventing mechanism permits withdrawal of tack body thereby separating the tack assembly and article from the tag body. A sensor detectable by an electronic article surveillance system is disposed in said tag body. An alarm is disposed within the tag body, for sounding an audible alarm if the tack assembly is withdrawn from the tag body without the arcuate probe being guided through the arcuate channel to the preventing means. A first switch put into a first state by the tack body upon insertion into the tag body. A second switch put into a first state by the tack head upon insertion of the tack body into the tag body. A third switch put into a first state by the arcuate probe when the arcuate probe is introduced into the arcuate channel to engage the receiving and clutching mechanism. The alarm sounds when the first switch is put into a second state without the third switch in its first state, and the alarm also sounds when the second switch is put into a second state without the third switch in its first state. An LED or other light-emitting device can be made visible on the exterior of the tag body to periodically flash when the alarm is armed. A plurality of relatively small apertures can be disposed on the tag body to permit the audible sound from the alarm to travel from the interior of the tag body to the exterior of the tag body. The plurality of apertures covers a sufficient portion of the tag body to prevent external localization of the position within the tag body of a sound emitting mechanism for generating the sound from the alarm.
A magnet switch for triggering the alarm when a relatively strong magnetic field is incident on the tag body can be included.
A lanyard can be used to attach the tag to an article. The alarm can sound when the lanyard is cut or broken or otherwise becomes discontinuous.
A shield can be provided in said tag body adjacent the sensor to prevent insertion of an instrument through the tag body and into the sensor to damage the sensor.
A shield can be disposed in the tag body adjacent the releasing and clutching mechanism to prevent unauthorized release of the receiving and clutching mechanism by other than the arcuate probe.
In a fifth aspect of the present invention a method for alarming an electronic article surveillance tag having a tag alarm disposed within a tag body, the tag body adapted to receive a tack assembly for releasable attachment of the tag to an article. The method includes providing an electronic article surveillance tag having an internal circuit for sounding an audible alarm in response to unauthorized detachment of the tag. Arming the tag alarm by insertion of a tack assembly into a tag body and sensing a first state of a tack switch, a first state of a plunger switch, and the first state of an on/off switch. Activating the tag alarm upon sensing a second state of the tack switch and the first state of the on/off switch. Activating the tag alarm upon sensing a second state of the plunger switch and the first state of the on/off switch. And, unarming the tag alarm upon sensing the second state of the on/off switch.
Sensing a relatively strong magnetic field incident on the tag body can activate the tag alarm. Sensing a discontinuity in an attached lanyard can activate the tag alarm.
In a sixth aspect of the present invention, an electronic article surveillance system having an electronic article surveillance tag attachable to an article, the electronic article surveillance tag includes a tag body and with a tack assembly for attaching the tag body to an article. The tack assembly includes a tack head and a tack body, which is receivable in the tag body and the tag body is provided with a preventing mechanism for releasably preventing withdrawal of the tack body. Channel defining structure within the tag body defines an arcuate channel. This channel leads to the preventing mechanism and permits an arcuate probe to be guided to such mechanism for releasing same. Release of the preventing mechanism permits withdrawal of tack body thereby separating the tack assembly and article from the tag body. A sensor detectable by an electronic article surveillance system is disposed in said tag body. An alarm, disposed within the tag body, for sounding an audible alarm if the tack assembly is withdrawn from the tag body without the arcuate probe being guided through the arcuate channel to the preventing mechanism. A transmitter for transmitting a first signal into a surveillance zone. A receiver for receiving a tag signal resulting from the interaction in the surveillance zone of the first signal with the detectable electronic article surveillance sensor in the tag body for detecting the presence of the tag in the surveillance zone.
In a seventh aspect of the present invention, an electronic article surveillance system having an electronic article surveillance tag attachable to an article, the electronic article surveillance tag includes a tag body and with a tack assembly for attaching the tag body to an article. The tack assembly includes a tack head and a tack body, which is receivable in the tag body and the tag body is provided with a preventing mechanism for releasably preventing withdrawal of the tack body. Channel defining structure within the tag body defines an arcuate channel. This channel leads to the preventing mechanism and permits an arcuate probe to be guided to such mechanism for releasing same. Release of the preventing mechanism permits withdrawal of tack body thereby separating the tack assembly and article from the tag body. A sensor detectable by an electronic article surveillance system is disposed in said tag body. A shield is provided in said tag body adjacent the sensor to prevent insertion of an instrument through the tag body and into the sensor to damage the sensor. A transmitter for transmitting a first signal into a surveillance zone. A receiver for receiving a tag signal resulting from the interaction in the surveillance zone of the first signal with the detectable electronic article surveillance sensor in the tag body for detecting the presence of the tag in the surveillance zone.
In an eighth aspect of the present invention, an electronic article surveillance system having an electronic article surveillance tag attachable to an article, the electronic article surveillance tag includes a tag body and with a tack assembly for attaching the tag body to an article. The tack assembly includes a tack head and a tack body, which is receivable in the tag body and the tag body is provided with a preventing mechanism for releasably preventing withdrawal of the tack body. Channel defining structure within the tag body defines an arcuate channel. This channel leads to the preventing mechanism and permits an arcuate probe to be guided to such mechanism for releasing same. Release of the preventing mechanism permits withdrawal of tack body thereby separating the tack assembly and article from the tag body. A sensor detectable by an electronic article surveillance system is disposed in said tag body. A shield is disposed in the tag body adjacent the releasing and clutching mechanism to prevent unauthorized release of the receiving and clutching mechanism by other than the arcuate probe. A transmitter for transmitting a first signal into a surveillance zone. A receiver for receiving a tag signal resulting from the interaction in the surveillance zone of the first signal with the detectable electronic article surveillance sensor in the tag body for detecting the presence of the tag in the surveillance zone.